Chapter 16: Molecular Chain Packing and Conformation in π-Conjugated Polymers from Solid-state NMR

Polymers with extended π-conjugation are currently of broad scientific interest due to their promising applications as the active semiconducting material in flexible organic electronic devices. The main advantage of using π-conjugated polymers is that this enables the fabrication via solution processing. However, this yields materials that are semicrystalline, potentially lacking any long-range order, and prevents direct access to details about the molecular organization from a conventional approach. In this chapter, we first provide the reader with a brief introduction to the area of semiconducting π-conjugated polymers and the challenges associated with characterizing their structure at the molecular level. This is followed by a selected overview of 1D and 2D solid-state NMR techniques that are capable of elucidating the molecular chain packing and conformation for semicrystalline π-conjugated polymers. Finally, three examples are given highlighting how the selected NMR techniques can be used to gain molecular insights into this kind of material.